Vehicle Height Shown in Cab

[TR673]

How accurate is the "overall height" information written in the cabs of buses, and is it the responsibility of the manufacturer or operator to assign it?

The reason I ask is because I've been trying to take note of the height information on as many double deck types as I can find, yet sometimes identical vehicles seem to have considerable variation. E.g. I've seen an instance of one Wright Gemini bodied B7TL plated at 4394mm and another plated at 4570mm! And online I've seen conflicting info on whether a low height E400 is 4.2 or 4.3m.

Research findings so far:
Scania N230UD Enviro 400 = 4318mm (Nottingham CT)
Scania N230UD Omnidekka = 4240mm (Nottingham CT)
Scania N230UD Olympus = 4300mm (Reading Buses)
ADL Enviro 400 full height= 4420mm (Stagecoach, ex Cambridge P&R)
Dennis Trident ALX400 low height= 4200mm (Stagecoach)
Dennis Trident ELC Myllennium = 4335mm (ex Blackpool)
Volvo B7TL Wright Gemini = 4570mm (ex Lincs Road Car)
Volvo B7TL Wright Gemini = 4394mm (Go North East)
Volvo B7TL ALX400 full height (?) = 4340mm (ex Dublin)
Volvo B7TL ALX400 medium height = 4295mm (ex First)
Volvo B7TL ALX400 low height = 4200mm (ex First)

Does anybody else take note of this stuff and have any other vehicle types to add, or the same types that either align/differ from what I've seen? Or even just any more insight into how the heights are calculated, who measures it, whether it includes tree deflectors etc?

 

[Mark L]

How accurate is the "overall height" information written in the cabs of buses, and is it the responsibility of the manufacturer or operator to assign it?

The reason I ask is because I've been trying to take note of the height information on as many double deck types as I can find, yet sometimes identical vehicles seem to have considerable variation. E.g. I've seen an instance of one Wright Gemini bodied B7TL plated at 4394mm and another plated at 4570mm! And online I've seen conflicting info on whether a low height E400 is 4.2 or 4.3m.

Research findings so far:
Scania N230UD Enviro 400 = 4318mm (Nottingham CT)
Scania N230UD Omnidekka = 4240mm (Nottingham CT)
Scania N230UD Olympus = 4300mm (Reading Buses)
ADL Enviro 400 full height= 4420mm (Stagecoach, ex Cambridge P&R)
Dennis Trident ALX400 low height= 4200mm (Stagecoach)
Dennis Trident ELC Myllennium = 4335mm (ex Blackpool)
Volvo B7TL Wright Gemini = 4570mm (ex Lincs Road Car)
Volvo B7TL Wright Gemini = 4394mm (Go North East)
Volvo B7TL ALX400 full height (?) = 4340mm (ex Dublin)
Volvo B7TL ALX400 medium height = 4295mm (ex First)
Volvo B7TL ALX400 low height = 4200mm (ex First)

Does anybody else take note of this stuff and have any other vehicle types to add, or the same types that either align/differ from what I've seen? Or even just any more insight into how the heights are calculated, who measures it, whether it includes tree deflectors etc?

The ADL website gives options of 4.2m or 4.3m for an Enviro400. The latter is a tad over 14’1” in old money so lower than many full height double deckers of old but obviously higher than the 4.2m version!

 

[Merle Haggard]

I though that clearance heights had to be shown in imperial but perhaps that only applies to signs on the highway.

 

[TR673]

I though that clearance heights had to be shown in imperial but perhaps that only applies to signs on the highway.

To be fair all the measurements were duplicated in imperial but I'd only written the metric ones down. I think metric is optional on road signs but usually included?

In fact that reminds me something else I was going to originally ask about.
I know there are some cases where signs showing both units don't match up to the measurements in the cab, so imperial reckons it's ok but over height according to the metric conversion! In that case who is liable if a vehicle strikes a bridge which is clear under one measurement but not the other?

 

[Merle Haggard]

To be fair all the measurements were duplicated in imperial but I'd only written the metric ones down. I think metric is optional on road signs but usually included?

In fact that reminds me something else I was going to originally ask about.
I know there are some cases where signs showing both units don't match up to the measurements in the cab, so imperial reckons it's ok but over height according to the metric conversion! In that case who is liable if a vehicle strikes a bridge which is clear under one measurement but not the other?

There's something on the web about these variations which seem to be due to laid-down rules for rounding from the exact dimension which is done for each set of units separately. Possibly with different rounding criteria between the two systems. Sometimes the variation is quite wide.
Your point is an interesting because if you pass the red circle signs with a vehicle of greater height than shown on the notice you are technically committing an offence even if you pass safely through.